Watched it again and the beginning said first Kaiju attack was in 2013. Then increased slowly over the years. The year was 2020 when they cut the funding for the jaeger program for 8 months left available. So by the time the lead rejoins, it could have been the next year in 2021 or even further. Sounds like Hannibal Chau has been funding the Jaeger program for quite a while giving him exclusive rights to the Kaiju when they're dead. So I am thinking the lead rejoins in 2022-2025.
Mako is a lil girl when Pentecost saves her if the 2013 being the first attack, I don't think she'd be old enough to pilot a Jaeger in 2021, 8 years... unless she's like 15 years old lol. So anybody guess what year it really is at the end. I am leaning more towards 2025-2030.
I hope the sequel covers a lot of my questions and hopes/dreams for any sequel being full of action.